The papacy has a spiritual and institutional meaning in the Catholic Church and an historical meaning.
When used in the context of the Catholic Church, the papacy refers to the office of pope, the successor of St. Peter, and the authority that the pope exercises in that office.
When used historically, the papacy often refers to a particular pope’s time in office, or the religious and cultural force of the Catholic Church down through history.
The papacy was instituted by Christ when he told St. Peter that, “upon this rock, I will build my Church.”
The papacy of Pope Paul VI was a time of marked change in the Church and the world.